History
– Busways originated in Detroit in the late 1920s, driven by the automotive industry’s demand.
– Over time, busways evolved and became an integral part of secondary networks for industrial plants.
Construction
– Bus ducts consist of aluminum sections with sandwiched bus bars.
– The interior of bus ducts reveals plastic wrappings of the busbars and hollow plastic tube spacers.
– Individual busbars are often wrapped or coated with a non-conducting material, such as plastic or electrical tape.
– Busbars may be separated with distinct gaps or sandwiched together.
– Bus ducts have thicker, cold-formed steel side rails and thinner sheet metal coverings, similar to cable trays.
Functionality
– Plug-in bus duct systems allow for the easy movement of devices like switches and motor starters.
– Feeder busway interconnects equipment, such as transformers and switchgear line-ups.
– Low-impedance busway reduces voltage drop through close spacing of bus bars.
– Trolley busway provides power to frequently moved equipment using a movable collector assembly.
– Bus ducts must be externally firestopped when penetrating fire separations with a fire-resistance rating.
Related Concepts
– Bus (computing)
– Busbar
– Isolated-phase bus
– Duct (flow)
References and External Links
– IEEE 3001.5-2013 – IEEE Recommended Practice for the Application of Power Distribution Apparatus in Industrial and Commercial Power Systems.
– American Electricians Handbook Eleventh Edition, Terrel Croft and Wilford Summers (ed), McGraw-Hill 1987, ISBN 0-07013932-6, pages 9-114 through 9-132.
– Wikimedia Commons has media related to Bus ducts. Source: https://en.wikipedia.org/wiki/Bus_duct
In electric power distribution, a bus duct (also called busway) typically uses sheet metal, welded metal or cast resin to contain and isolate copper or aluminium busbars for the purpose of conducting a substantial current of electricity. It is an alternative means of conducting electricity to power cables or cable bus.
Originally a busway consisted of bare copper conductors supported on inorganic insulators, such as porcelain, mounted within a non-ventilated steel housing.
